Laurus nobilis, ext.

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Study period:

1985

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Non adjuvant method, relevant deficiencies. Uncovered test site. Application site changed if very strong reactions provoked. No detail on test results / dose tested and selection.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1985

Materials and methods

Principles of method if other than guideline:

Method: Open epicutaneous test

GLP compliance:

not specified

Type of study:

open epicutaneous test

Test material

Test material information

Constituent 1

Reference substance name:

Laurus nobilis, ext.

EC Number:

283-272-5

EC Name:

Laurus nobilis, ext.

Cas Number:

84603-73-6

IUPAC Name:

Laurus nobilis, ext.

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): Laurel leaf oil

In vivo test system

Test animals

Species:

guinea pig

Strain:

not specified

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 300-450 g

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, open

Vehicle:

other: unchanged or concurrent vehicle

Induction 2

Concentration / amount:

Range finding tests: 1, 3, 10, 30 and 100 %
Main test:
- Induction phase: 0.3, 1, 3, 10, 30 and 100 %
- Challenge phase: Minimal irritating and some lower primary non-irritating concentrations

Challenge

Challenge 1

Route:

epicutaneous, open

Vehicle:

other: unchanged or concurrent vehicle

Challenge 2

Concentration / amount:

Range finding tests: 1, 3, 10, 30 and 100 %
Main test:
- Induction phase: 0.3, 1, 3, 10, 30 and 100 %
- Challenge phase: Minimal irritating and some lower primary non-irritating concentrations

No. of animals per dose:

At least 6 animals in each treatment group (maximum: 20) and 10 animals in control group

Details on study design:

RANGE FINDING TESTS: On a day before starting the exposure (Day -1), a single application of 0.025 mL of each test concentration (1, 3, 10, 30 and 100 %) was simultaneously performed on clipped flank skin (2 cm2) of 6-8 animals and the reactions were recorded after 24 h. The minimal irritating and the maximal non-irritating concentrations were determined by an all-or-none criterion.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 21
- Test groups: Open epicutaneous application of 0.1 mL of each test concentration (0.3, 1, 3, 10, 30 and 100 %)
- Control group: No treatment or topical (uncovered) application of 0.1 mL of vehicle
- Site: Clipped flank skin (8 cm2)
- Frequency of applications: Daily for 3 weeks or 5 times weekly for 4 weeks, usually on the same skin sites. When very strong skin reactions were provoked, the application sites were changed.
- Duration: Days 0-20
- Evaluation: Dermal reactions were recorded at 24 h after each application or at the end of each week and the minimal irritating and the maximal non-irritating concentrations were determined by an all-or-none criterion.

B. CHALLENGE EXPOSURE
- No. of exposures: 2
- Day(s) of challenge: Days 21 and 35
- Test and control groups: Open epicutaneous application of 0.025 mL of minimal irritating and some lower primary non-irritating concentrations of the test material
- Site: Contralateral flank (2 cm2)
- Evaluation (h after challenge): 24, 48 and/or 72 h

Challenge controls:

Open epicutaneous application of 0.025 mL of minimal irritating and some lower primary non-irritating concentrations of the test material was performed on control animals during challenge phase.

Positive control substance(s):

not specified

Results and discussion

Positive control results:

Not applicable

Any other information on results incl. tables

No positive reaction was observed after challenge exposure.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: not specified

Conclusions:

Under the test conditions, Laurel leaf oil was found to be a non-sensitiser to skin of guinea pigs in an open epicutaneous test (OET).

Executive summary:

In an open epicutaneous test (OET), groups of guinea pigs were topically (uncovered) induced with 0.1 mL of Laurel leaf oil at doses of 0.3, 1, 3, 10, 30 and 100 % on clipped flank skin (8 cm2), daily for 3 weeks or 5 times weekly for 4 weeks, usually on the same skin sites. The application sites were changed if very strong skin reactions were provoked. At least 6 animals were used in each treatment group and 10 animals in control group. On Days 21 and 35, an open epicutaneous challenge application of 0.025 mL of minimal irritating and some lower primary non-irritating concentrations of the test material was performed on the contralateral flank (2 cm2) of the animals and the dermal reactions were recorded after 24, 48 and/or 72 h. Range finding test was conducted at the concentrations of 1, 3, 10, 30 and 100 % to determine the doses for main study.

No positive reaction was observed after challenge exposure.

Under the test conditions, Laurel leaf oil was found to be a non-sensitiser to skin of guinea pigs in an open epicutaneous test (OET).